Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
Waterloo's temperature records reveal December as the coldest month, marked by average highs of 45.3°F (7.4°C) and lows of 34.2°F (1.2°C).Humidity
January through March and December, with an average relative humidity of 86%, are the most humid months.Rainfall
December is the month with the most rainfall. Rain falls for 18 days and accumulates 4.41" (112mm) of precipitation.Snowfall
January through March, November and December are months with snowfall. In Waterloo, Oregon, during December, snow falls for 0.7 days and regularly aggregates up to 0.31" (8mm) of snow. In Waterloo, during the entire year, snow falls for 5.6 days and aggregates up to 4.09" (104mm) of snow.Daylight
The month with the shortest days is December, with an average of 8h and 54min of daylight.On the first day of December, sunrise is at 7:28 am and sunset at 4:32 pm. On the last day of the month, sunrise is at 7:47 am and sunset at 4:41 pm PST.
Sunshine
The average sunshine in December is 4.3h.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a minimal health vulnerability from unsafe exposure to UV radiation for the average person.Note: An average maximum UV index of 2 in December leads to these recommendations:
The majority are not significantly affected by prolonged sun exposure. Infants, children, and those with fair skin must always have protection. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days. Heed this! Snow reflection can almost augment the UV radiation of the sun by double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What part of the year is the coldest?
What is the average December temperature?
What is the most humid month?
What is the average humidity in December in Waterloo?
What is the rainiest month?
How much does it rain in Waterloo in December?
How much does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December?
When is the sunrise / sunset in December?
How many hours of sunshine does Waterloo have in December?
What are the months with the lowest UV index?
How high is the UV index in December?
Average temperature in December
Waterloo, OR
- Average high temperature in December: 45.3°F
The warmest month (with the highest average high temperature) is August (81.1°F).
The month with the lowest average high temperature is December (45.3°F).
- Average low temperature in December: 34.2°F
The month with the highest average low temperature is August (51.8°F).
The coldest month (with the lowest average low temperature) is December (34.2°F).
Average pressure in December
Waterloo, OR
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The months with the lowest atmospheric pressure are August and September (30.01"Hg).
Average wind speed in December
Waterloo, OR
- Average wind speed in December: 5mph
The windiest months (with the highest average wind speed) are January and March (5.1mph).
The calmest month (with the lowest average wind speed) is August (3.9mph).
Average humidity in December
Waterloo, OR
- Average humidity in December: 86%
The months with the highest relative humidity are January, February, March and December (86%).
The month with the lowest relative humidity is August (66%).
Average rainfall in December
Waterloo, OR
- Average rainfall in December: 4.41"
The wettest month (with the highest rainfall) is December (4.41").
The driest month (with the least rainfall) is July (0.24").
Average rainfall days in December
Waterloo, OR
- Average rainfall days in December: 18 days
The month with the highest number of rainy days is March (20.1 days).
The months with the least rainy days are July and August (3.8 days).
Average snowfall in December
Waterloo, OR
- Average snowfall in December: 0.31"
The month with the highest snowfall is February (2.13").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Waterloo, OR
- Average snowfall days in December: 0.7 days
The month with the highest number of snowfall days is February (2.5 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Waterloo, OR
- Average daylight in December: 8h and 5min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in December: 4h and 2min
The month with the most sunshine is August (Average sunshine: 11h and 12min).
The month with the least sunshine is February (Average sunshine: 4h and 12min).
Average sunshine days in December
Waterloo, OR
- Average sunshine days in December: 11.6 days
The month with the most sunshine days is July (25.6 days).
The month with the least sunshine days is March (9.1 days).
Average UV index in December
Waterloo, OR
- Average UV index in December: 2
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in December
Waterloo, OR
- Average cloud cover in December: 56
The month with the most cloud cover is February (Cloud cover 59).
The month with the least cloud cover is August (Cloud cover 20).
Average visibility in December
Waterloo, OR
- Average visibility in December: 5mi
The months with the highest visibility are July, August and September (6mi).
The month with the lowest visibility is February (4mi).
Waterloo, Oregon, USA
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